Apparatus for distributing a liquid volume into a number of receptacles

ABSTRACT

An analytical device for distributing equal portions of a certain liquid volume into a plurality of vessels, the device having a groove-shaped circular channel with the partially communicating vessels attached to its outer rim. Sufficient liquid is fed to the channel and allowed to overflow into the communicating parts of the vessels from where the individual portions of the liquid are forced into the non-communicating parts of the vessels by rotation of the device.

United States Patent 1191 1111 3,766,016 Guigan Oct. 16, 1973 [54] APPARATUS FOR DISTRIBUTING A 3,175,732 3/1965 Unger 141/34 LIQUID VOLUME INTO A NUMBER OF RECEPTACLES Inventor: Jean Guigan, 9 rue Jean-Mermoz,

Paris, France Filed: Nov. 9, 1970 Appl. No.: 87,681

US. Cl 195/140, 23/253, 141/34 Int. Cl C12k 1/10 Field of Search 195/127, 139, 139 LE,

References Cited UNITED STATES PATENTS 4/1971 Davis et al. 23/253 Primary ExaminerA. Louis Monacell Assistant Examiner-Robert M. Elliott AttorneyRichard C. Sughrue et a1.

[57] ABSTRACT An analytical device for distributing equal portions of a certain liquid volume into a plurality of vessels, the device having a groove-shaped circular channel with the partially communicating vessels attached to its outer rim. Sufficient liquid is fed to the channel and allowed to overflow into the communicating parts of the vessels from where the individual portions of the liquid are forced into the non-communicating parts of the vessels by rotation of the device.

8 Claims, 3 Drawing Figures Patented Oct. 1 1973 6 3,766,016

Imam ran JEAN GUIGAN APPARATUS FOR DISTRIBUTING A LIQUID VOLUME INTO A NUMBER OF RECEPTACLES This invention is concerned with an apparatus for the simultaneous distribution of a given volume of a liquid between a plurality of vessels so that each of said vessels receives a substantially equal volume of liquid.

One particular use of the invention lies in the field of the identification of bacteria. The identification of a bacteria is conventionally undertaken by distributing a culture medium, which has undergone a suitable incubation, between a plurality of vessels, each of which contains a different reagent. In general the vessels used are test-tubes, capillary tubes or hollows formed in a sheet of plastic.

Observations carried out on the behaviour with the different reagents gives an enzymatic profile of the bacteria which in turn enables the identification of the bacteria. An alternative method is to establish the antibiogram of the bacteria by distributing, in the same manner, a solution of the bacteria between vessels containing different antibiotics in a variety of doses.

The media have in the past conventionally been seeded one by one but since there are a large number of different media this operation was a long and delicate one.

It is an object of the present invention to provide an apparatus which permits the simultaneous and practically instantaneous (a few seconds) distribution of a liquid between a plurality of vessels.

According to the present invention there is provided an apparatus for dividing a given volume of liquid into a plurality of substantially equal portions, which comprises a plurality of tubes closed at one end and having an opening at the other end, the open ends of the tubes communicating with a common circular channel, the said circular channel being capable of communicating by means of radially directed conduits with a receptacle containing the liquid to be divided, the tubes being disposed substantially radially with respect to the said channel and the said tubes having two portions which form an obtuse angle with respect to each other.

Preferred embodiments of the invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is a cross-sectional elevation of an apparatus according to the present invention,

FIG. 2 is a plan of the apparatus of FIG. 1 and FIG. 3 is a plan ofa variation of the apparatus shown in FIG. 1.

The apparatus is in the general form of a disc and, in use, must be in the horizontal position. With reference to FIGS. 1 and 2 of the accompanying drawings the apparatus consists essentially of a circular channel 10, which is interconnected to a plurality of tubes 11, the said tubes being closed at their ends away from the channel 10.

The tubes 11 are disposed radially in relation to the channel 10. The tubes have a portion thereof 110 which is inclined upwardly from the horizontal and which leads to a portion thereof 111 which is inclined downwardly. The obtuse angle between the two portions of the tubes may conveniently be from 150 to nearly 180.

Furthermore the tubes are so disposed that the uppermost level of the channel is situated higher than the lowest point of the tube portion 110.

The circular channel 10 is connected by a series of radially disposed conduits (e.g., 20) with a central container 21 through which the liquid to be distributed can be introduced.

The conduits 20, the channel 10 and the tubes 11 are preferably closed by a plastic covering which renders the assembly hermetically sealed.

The central container 21 has, in its lower part, an opening 22 to which may be attached a small bulb 23 which is made of a flexible material such as rubber or a flexible plastic.

The entire disc assembly comprising the channel 10, the conduits 20, the central container 21 and the tubes 11 may conveniently be made out of plastic and be formed as a single piece obtained by moulding or casting.

For use in the identification of bacteria the assembly is sterilised and into each of the downwardly inclined portions 111 of the tubes 11 there is introduced a culture medium 112 containing a reagent.

For the purposes of identifying bacteria present in a given solution the following operations are carried out:

The bulb 23 is detached from its place. A suitable quantity of the solution is then sucked into the bulb which is then replaced on the apparatus. The bulb is then squeezed upwardly so that the liquid is forced into the receptacle 21 and passes, via the conduits 20, into the channel 10.

After having filled the channel 10 the liquid then overflows into the upwardly inclined portions of the radially directed tubes 11.

Once the level of liquid is equal in all the tubes 11 the pressure on the bulb 23 is relaxed. Thereupon the liquid remaining in the channel 10 and the central container 21 reflows back in to the interior of the bulb but the liquid which has overflowed into the tubes 11 remains in the upwardly inclined portion thereof 110 up to the level of the upper limit of the channel 10.

There is thus achieved the simultaneous distribution of a substantially equal quantity of liquid into each of the tubes 11.

The entire assembly consisting of the disc, tubes and bulb is then rotated about the planar axis of the disc. This movement may be limited to a fraction of a turn or may be more than several turns.

The rotation may be conveniently effected by placing the assembly of the disc and bulb on a support which rotates in the horizontal plane. Under the effect of the resulting centrifugal force the liquid present in the upwardly inclined portions 110 of the tubes 11 passes over into the downwardly inclined portions 111 which contain the culture media 112 and the reagents associated therewith.

This results in the simultaneous seeding of each of the media 112.

The combined operations do not require more than a few seconds.

After rotation, the degree of growth of the bacteria is measured by observing the colouration of the reagents contained in each of the tubes 11.

It is simple to effect an automatic measurement of the colourations by pivoting the disc about its axis in order to present successively each of the culture media before the measuring cell of a photometer.

It is thus possible to establish the enzymatic profile of a bacteria and hence to identify it.

If the culture media in the tubes 11 are replaced by a selection of different antibiotics, in dosages which differ from one tube to the next, it is possible, by proceeding according to the manner set out above, to obtain rapidly the antibiogram of a bacteria.

A further possibility is to employ a certain proportion of the tubes for the identification of the bacteria and to employ the rest for the determination of the antiboigram.

Referring now to FIG. 3 of the accompanying drawings there is shown a plan view of a portion of a disc assembly which is somehwat modified as compared with that shown in FlGS. 1 and 2, in that the tubes are not disposed perpendicularly with respect to the channel 110 but at an angle other than at a right angle. The tubes may thus conveniently be disposed at an angle of from 90 to 120 with respect to the tangent of the circular channel. This modified configuration facilitates the passage of the liquid from the zone 110 into the zone Ill during the rotational movement, on account of the inertia of the drops of liquid.

For the same reasons, the tubes 11 are not rectilinear but curved.

Apart from the above-mentioned advantages, the apparatus also has the advantage that the identification of a sample is only made once with respect to any part of the disc, as compared with the methods previously used in which it was necessary to identify individually each one of the tubes.

Modifications may of course be made to the specific embodiments of the invention described above without departing from the spirit of the invention which is set out in the following claims.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim 1. An apparatus for dividing a given volume of liquid into a plurality of substantially equal portions, which comprises; a common horizontal circular channel, a plurality of tubes closed at one end and having an opening at the other end, the open ends of the tubes communicating with said common horizontal circular channel, radially directed conduits fluid connecting said channel with a receptacle containing the liquid to be divided, said tubes being disposed substantially radially with respct to said channel at circumferentially spaced positions and having a first inner portion extending radially outwards from the outer edge of said circular channel with its inboard end lying below the level of said edge, said first tube portions being inclined upwardly and terminating in second tube portions inclined downwardly and forming with said first portions an obtuse angle whereby a given volume of liquid is captured at the inboard end of each first tube section by liquid overflow of the outer lip of said circular channel permitting the captured given volume of liquid to subsequently flow within each tube to said second tube portion.

2. An apparatus as claimed in claim 1 wherein the central container has an opening in the lower part thereof which is adapted to receive a bulb for injecting the liquid to be divided.

3. An apparatus as claimed in claim 1 wherein the radially disposed tubes are disposed at an angle of from to to the tangent of the circular channel.

4. An apparatus as claimed in claim 1 wherein the portions of the tube lie at an obtuse angle from from to nearly to each other.

5. An apparatus as claimed in claim 1 wherein the downwardly inclined portions of the tubes contain culture media and reagents.

6. An apparatus as claimed in claim I wherein the apparatus is cast or moulded as a single unit and the radial tubes and conduits are in the form of channels which are adapted to be closed by a lid which also covers the circular channel.

7. An apparatus as claimed in claim 6 wherein the lid is made of plastic.

8. An apparatus as claimed in claim 6 wherein the lid is made of rubber. 

2. An apparatus as claimed in claim 1 wherein the central container has an opening in the lower part thereof which is adapted to receive a bulb for injecting the liquid to be divided.
 3. An apparatus as claimed in claim 1 wherein the radially disposed tubes are disposed at an angle of from 90* to 120* to the tangent of the circular channel.
 4. An apparatus as claimed in claim 1 wherein the portions of the tube lie at an obtuse angle of from 150* to nearly 180* to each other.
 5. An apparatus as claimed in claim 1 wherein the downwardly inclined portions of the tubes contain culture media and reagents.
 6. An apparatus as claimed in claim 1 wherein the apparatus is cast or moulded as a single unit and the radial tubes and conduits are in the form of channels which are adapted to be closed by a lid which also covers the circular channel.
 7. An apparatus as claimed in claim 6 wherein the lid is made of plastic.
 8. An apparatus as claimed in claim 6 wherein the lid is made of rubber. 